Evaluation of natural killer cell activity in patients with persistent generalized lymphadenopathy and acquired immunodeficiency syndrome.

Natural killer (NK) cell activity was quantitated using 51Cr release from the human erythroleukemia cell line K562 in 39 heterosexual males, 60 asymptomatic homosexuals, 39 patients with persistent generalized lymphadenopathy (PGL), and 16 patients with acquired immunodeficiency syndrome (AIDS). PGL and AIDS patients showed a slight decrease in NK cell activity compared to control groups. Absolute numbers of Leu 11a-positive cells were decreased in PGL and AIDS patients, and this decrease correlated with a decrease in absolute number of both the T4+ and T8+ cell subsets. Autologous plasma inhibited NK cell activity in 48% of asymptomatic homosexuals, 63% of PGL patients, and 63% of AIDS patients, but in none of the heterosexual controls. NK cell responses in fetal calf serum, normal human plasma, or autologous plasma showed no correlation with absolute numbers of T4+ cells, or with T4/T8 ratio. We conclude that NK cell responses are not of prime importance in the pathogenesis of PGL and AIDS.